Uluru, also known as Ayers Rock and officially gazetted as Uluru / Ayers Rock, is a large sandstone monolith. It outcrops near the centre of Australia in the southern part of the Northern Territory, 335 km (208 mi) south-west of Alice Springs.

A monolith is a geological feature consisting of a single massive stone or rock, such as some mountains. Erosion usually exposes the geological formations, which are often made of very hard and solid igneous or metamorphic rock. Some monoliths are volcanic plugs, solidified lava filling the vent of an extinct volcano.